It is surprising to find pieces of piston in the pan when you open her up. If the thing has blown up is one thing but if it is running Ok is something else. I have found bits and pieces of pistons in pans quite a few times. For some reason I have found the "tails" of pistons several times in otherwise Ok engine pans. I just put the pan back on and let em run.
I never saw a floating piece of piston like you describe though. Don't deglaze too much deglazing is WEAR too.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

professional bovine relocation specialist